Originally Posted By: Alex
Regarding the typical baseplate compass measurements precision. I meant the compound accuracy (mechanics, techniques, conditions). I said it is 10 degrees. You are insisting on +/- 3 degrees, but that's 6 degrees overall. Add dial/needle/sight view parallax errors, add lack of levelness, add impatience for needle setting - and you can round it up to 10 without a single doubt (I'm leaving magnetic anomalies and lack of mag.dec. precise knowledge outside of the scope). And that's exactly the ancient compass technology flaws, you have mentioned yourself, as the primary source of these errors.

Alex, I'm afraid I have to politely disagree with you. It is entirely possible for a careful user to get within +/- 2 degrees using a mirror compass. This includes ALL of the compound errors. I have participated in compass training exercises which required walking a course and finding small, obscure targets. If you were more than 2 degrees off over a distance of 100 to 200 meters, you would walk on by and not find the correct target.

This kind of accuracy does require careful work, but it is doable.
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